A comprehensive understanding of solvent mediated ion pair formation between ionic solutes at the molecular- and mesoscale level remains elusive. This knowledge gap prevents the straightforward tailoring of material formulations for bulk ionic solution (i.e. electrolytes), property optimization and control of interfacial interactions relevant to many biological and chemical reactions. This project focus on the effect of oxidation state and molecular size of redox active ions on preferential ion-pair formation in complex solvent mixtures. Fundamental percipience of solvent-ion and ion-ion interactions and the variance in these solutions for differing charge and molecular size of ionic solutes will be assembled using multi-modal spectroscopic and computational analysis. A team of researchers with expertise in demystifying the solvation structure and dynamics within liquid electrolytes will fuse complementary experimental (NMR, EPR and Raman spectroscopy) and computational (DFT calculations, AIMD simulations) methods together, utilizing the exceptional resources available at EMSL. Gleaned information regarding constitutive interactions will be correlated to conductivity, viscosity, and electrochemical/thermal stability of electrolyte solution.